At present, communication technologies like Bluetooth, Infrared Data Association (IrDA), Near Field Communication (NFC) and Radio Frequency Identification (RFID) are widely used in short-range communication, all of which applies electromagnetic wave. The Bluetooth technology needs users' participation to establish a communication connection, thus is not suitable for applications requiring rapid transmission (e.g., settlement and payment). Further, Bluetooth chips are typically very expensive and have a poor anti-interference capability. The IrDA technology is a kind of line-of-sight transmission, which thereby has its inherent deficiency, that is, devices communicating with each other should be aligned mutually and without separating object therebetween. Thus the IrDA technology is adapted for the communication connection between two devices (not for multiple devices), however, with a poor reliability, security, anti-interference and low data transmission rate. NFC technology, working at a frequency of 13.56 MHz within 20 cm, employs bi-directional identification and connection, and is currently considered to be the most secure short-range communication technology. However, the number of devices that supports NFC is still far from reaching the critical mass. RFID is currently widely applied in small amount payments, like public transportation cards, because of its low cost and reliable technology protocols. An alternative solution is to embed or stick specific RFID chips to user's carry on mobile device. It takes time and cost to roll it out to the mass. Barcodes, including a one-dimensional barcode and a two-dimensional barcode, are also common short-range scanning data transmission solutions. For one-dimensional barcode, it costs low in scanner, but scanners have a low accuracy in recognizing electronic displaying barcodes. For two-dimension barcode, it has good fault tolerance and recognition accuracy, but it costs high in scanning terminals because of a need for macro lenses, has a large number of standards, works unsatisfactorily in scanning time, and has specific requirements for client's display. The table below illustrates applicability of the technologies mentioned above to the requirement of the short-range communication between a mobile terminal and a commercial cashier system. Currently, there is no perfect technology meeting all the requirements shown in the table. A system and method of data communication based on non-contact sound wave or audio transmission according to the present disclosure has a better applicability.
Trans-Universal-User'sBusinessmissionrequirementreliabilitysecurityitycostcosttimepaymenttechnologyBluetoothhighhighmediumlowmediumslowYesIrDAlowlowlowNon-mediumslowNosupportNFChighverylowhighmediumquickYeshighRFIDhighhighlowlowhighquickYesBarcodemediumlowhigh0mediummediumNoscanning2-Dhighlowhigh0highslowNobarcodescanningpresenthighMedium/high0lowmediumYessoundhighsolution
There are some patents referring to sound wave application in data communication, such as Chinese patent application 99808078.0 by SIEMENS, and Chinese patent application 200710080253.4, entitled “Transmitter and receiver based on ultrasound, system and method using the same”. Both of the applications relates to transmission accomplished by using specific ultrasound wave (a specific frequency of sound wave). A problem existing in the sound wave solution is poor security, which is a price paid for the convenience of transmitting through the air, that is, sound is easily to be duplicated by recording, which limits the progress of sound wave as the secure data transmission medium to applications less sensitive to secure data.
FIG. 1 illustrates a situation that sound wave is recorded when transmitting. In FIG. 1, the serial number in circle is in the order of time.
{circumflex over (1)}â describes that a user plays coded sonic signals via a speaker in a mobile phone, and the data information (e.g., discount code) is transmitted to a cashier terminal, or to a receiver connected to the cashier terminal for receiving audio data or sonic data.
{circumflex over (1)}{circumflex over (b)} describes that a malicious user in the vicinity records the sonic signals transmitted through the air by using a hypersensitive recording device.
{circumflex over (2)} describes that the malicious user plays the recorded sonic signals to a cashier terminal, or to a receiver connected to the cashier terminal for receiving audio data or sonic data using a mobile phone or other specific mobile devices, intending to pay by using the settlement account information (discount coupon or payment card) of previous mobile user.
Therefore, there is a need for a secure transmission link which has ability to identify and prevent a potential safety hazard.